No matter where you are on Metallica's current tour – backstage, at sound checks, on the tour bus, in hotel lobbies or, most definitely, in hotel bars – that is the question on everyone's mind. It's scrawled on almost all of the band's equipment cases, the last word usually spelled kidz. It's the standard Metallica response to every unavoidable road chore or promotional nuisance – such as doing a press interview or making nice with the second cousin of a heavy local DJ who doesn't play the band's records anyway – "But what about the kids?" someone inevitably groans.

But what about the kids? Well, they went berserko at the city hall in Sheffield, England, tonight. They pounded their fists on chairs, railings, walls and each other. They screamed themselves hoarse. And they kept up a two-hour orgy of head banging and stage diving, looking less like a concert audience than a hurricane sea of denim, hair and black biker leather. While Metallica filled the smoky, sweaty air with its fierce thrash and lyric exhortations on death, disaster and heavy-metal brotherhood, the assembled teenage horde went ape. You have not lived the metal-concert experience until you've seen more than 2000 rock & roll animals bellowing in unison to Metallica's supersonic cover of "Last Caress," by the legendary punk gore hounds the Misfits: "I've got something to say/I killed your baby today!"

Now about a hundred of those animals are standing in the near-freezing cold outside the backstage door, hoping to get an autograph or at least to shake a hand when the band finishes toweling down and heads for the bus. Instead, "the kids" are all ushered inside, a dozen at a time to keep things orderly. They find the four members of Metallica – singer-guitarist James Hetfield, guitarist Kirk Hammett, bassist Jason Newsted and drummer Lars Ulrich – sitting at a table ready to give autographs, pose for photos and shoot the shit like normal everyday metalheads. They oblige their fans for the next hour and a half, signing everything thrust in front of them and listening intently to the fans' critiques of the evening's set. For Metallica, this is standard aprés-gig operating procedure, as much a part of the evening as the show itself. "I remember back when I stood outside for three hours waiting for autographs," says Hetfield later. "And when the star just hopped in his limo and took off, I'd think, 'You dick, I hate you.' I'd go home, rip down his posters. When there's a hundred kids outside, that don't bug me. They're there to see me. If they want my autograph, that's cool. "We know where they're coming from," Hetfield says, "because we've been there."

The phrase "But what about the kids?" is not a Metallica invention. Hetfield explains that the band's regular photographer, Ross Halfin, was on tour with Iron Maiden and that "he was telling one of their lighting guys, 'Hey, man, those red lights – you gotta get rid of them. They look like shit in photos.' And the lighting guy says, 'But what about the kids? The kids need red lights!"'

So Metallica gives 'em red lights, autographs and more, including one of the few truly raging stage shows making the 1988--89 arena rounds. It's a fair trade, too. Because it's the kids who have bought over a million copies of Metallica's latest album,... And Justice for All, zooming it straight into the Billboard Top Ten. And it was the kids who put the band's 1984 LP, Ride the Lightning, its 1986 LP, Master of Puppets, and its 1987 "covers" EP, Garage Days Re-Revisited, in the gold- and platinum-record winners' circles. It was the underground maniacs who were banging their heads to Metallica's legendary demo tapes and bazooka-metal LP debut, Kill 'Em All, back in '82 and '83, doing a word-of-mouth blitz on this killer California band that played everything faster than the speed of light and didn't put on any jive rock-star airs. It was the newcomers who saw Metallica's roaring bottom-of-the-bill sets last summer on the Monsters of Rock stadium tour and then bought more than enough Metallica gear at the merchandise stands to embarrass the headliners.

For years, the mainstream rock press dismissed the band, in Kirk Hammett's words, as "ugly guys singing ugly things to ugly music." AOR radio, for the most part, still doesn't want to know about them. Yet with only the kids in their corner and their own proud refusal to play traditional industry tiddlywinks (make promo videos, keep songs to four minutes or less) to fall back on, they have nevertheless become one of America's biggest bands, heavy metal or otherwise. There's plenty of metal atop the charts these days; most of the bands play the industry game well, making radio-ready records that inevitably include the so-called power ballad, aimed squarely at the Top Forty housewives and their teenage daughters. The members of Metallica can boast platinum sales with zero sellout, making records for themselves yet sating the collective hunger of America's metal militia.

They know instinctively what kids want – because they are the kids. When the fledgling Metallica made its vinyl debut on the 1982 indie compilation LP Metal Massacre, founders James Hetfield and Lars Ulrich were barely out of high school. Raised on a steady Seventies diet of Black Sabbath and Led Zeppelin, they were also psyched up by the new wave of street-smart British heavy-metal bands such as Diamond Head, Iron Maiden and the high-speed Motörhead. In turn, they created Metallica as a composite of everything they loved most about metal (the raunch, the volume, the physical release) and hated most about showbiz bullshit (spandex pants, songs about slaying dragons and painted ladies). With Hammett, purloined from a San Francisco band called Exodus, and the late bassist Cliff Burton, who died tragically in a bus accident during a 1986 Scandinavian tour, Hetfield and Ulrich pursued that sound and vision with a diligence that mocked accepted chart formulas.

American guitarist and singer James Hetfield of the heavy metal group Metallica performs onstage at the Robert F Kennedy Memorial Stadium, Washington DC, June 10, 1988. Tony Mottram/Getty

At the same time, they appealed to a new metal generation for whom Zeppelin and Sabbath were granddads but Quiet Riot and Mötley Crüe were too glam. "Metallica really created a form of music," says Brian Slagel, the enterprising metal fan who issued Metal Massacre on his own Metal Blade label, now a flourishing subsidiary of Enigma Records. "When they came out, there was no speed metal or thrash metal. They were doing something new, and if you look at bands who are successful, especially in this genre, they have to be doing something different and do it well."

Ozzy Osbourne recognized the inevitable future of metal when Metallica did six months as his opening act in 1986. "He told us, 'Man, you guys remind me of Sabbath in their early days – hungry, all the energy,"' says Hetfield, who's twenty-five. "And we thought, 'Fuck, that's a hell of a compliment."' And when longtime fan Jason Newsted, formerly a member of the Arizona thrasher band Flotsam and Jetsam, passed the bass audition following Burton's death, he knew that he wasn't just in for a nice paycheck. "I knew they were destined to make a huge mark – that they're just beginning to make now," says the twenty-five-year-old Newsted. "Metallica is going to be one of the bands you look back on in the year 2008, that people will still listen to the way I still listen to Zeppelin and Sabbath albums."

"But we always tried so hard just to be ourselves," says Ulrich, who's also twenty-five. "People ask me all the time, 'How do you do this? How do you do that?' I don't know. Shit happens. "When we put this band together, it was never about touring, making records, doing interviews. It was about playing some songs in a garage every night. It sounds so fucking unreal when they call from the office and say, 'Today we sold so many records."' "Theoretically," says Hammett, 26, "this never should have happened."

Today, when Metallica hits the stage, the members of the audience are confronted with a mirror image of themselves – shirts, jeans, shoulder-length hair untouched by mousse. They find James Hetfield rapping from the stage as though they were all sharing a six-pack out in a 7-Eleven parking lot – "Do you fuckers have the album Kill 'Em All? You wanna hear some old shit? Then you figure out what the fuck this is!" The kids also hear songs that address their own anxieties, such as suicide ("Fade to Black"), drug addiction ("Master of Puppets") and spiritual isolation (almost anything on Justice), rendered with a frenzy equal to their own nervous adolescent energies.

It is a sound that Hetfield aptly describes as "fucking huge shit": Hetfield and Hammett spit out pithy serrated riffs on their guitars while Ulrich and Newsted execute dizzying accelerated time changes with muscular aplomb. And it is a sound – compounded by Hetfield's crude vocal howl and the blunt, declamatory tone of his lyrics – that communicates in no uncertain terms how the members of Metallica feel about the world their elders have left them and where they can stick it. "The kids know that at the end of the day there's something very real and honest about what we do," claims Ulrich. "Whether you like it or dislike it, you can't take that away from us."

Lars Ulrich saw his first rock concert when his father, a Danish tennis pro, dragged him along to see Deep Purple in Copenhagen in 1973. Lars was nine years old. "I started very early," he says with a laugh. Young James Hetfield fell under the heavy-metal spell while rooting through his older stepbrother's record collection in suburban Los Angeles. "I was always looking for something different, something other people didn't always dig," he says. "When I was into Black Sabbath, all my friends would go, 'Oh, my mom won't let me have that album. It's scary, and I'll have nightmares.' I thought that was funny, so I had to go out and get it. "The Beatles and shit like that," he adds, "I never dug so much." Oddly enough, Metallica's tour manager, Bobby Schneider, was playing a tape of Abbey Road on the band bus not long ago. When the big guitar crescendo in "I Want You (She's So Heavy)" came on, Hetfield piped up, "Hey, what's that? That's pretty fucking hot." "I said, 'Man, that's the fucking Beatles,"' says Schneider. "He'd never heard it before."

What he'd never heard hadn't hurt him. Metallica's singular musical power and defiant outlaw pride is a unique, distinctly Eighties product of ardent fandom and a strange kind of rootlessness, as if the Sixties had never happened. Growing up amid the artistic malaise and commercial doldrums of mid-and late-Seventies rock, Hetfield and Ulrich – like many other sons and daughters of Woodstock Nation – were turned on by the physical vitality of heavy metal while rejecting the artifice of superstardom left over from the Sixties rock explosion. Ulrich in particular was a serious devotee of the New Wave of British Heavy Metal, a short-lived explosion between 1979 and 1981 of young metal bands that played a toughened variation on regulation HM and issued their own independent records and tapes. Ulrich, who moved with his parents to L.A. in 1980, went so far as to fly to London on his own in the summer of 1981 just to see his favorite NWOBHM bands, which included Motörhead, Saxon and Tygers of Pan Tang.

He became especially friendly with Diamond Head, a quartet respected in NWOBHM circles for its tight complex arrangements and gritty guitar attack. He even lived with the band for a month. "I used to go over to the singer's house, and we'd write in his bedroom," says Diamond Head guitarist Brian Tatler. "And Lars would be there, hanging out while we were laboring over arrangements, probably thinking, 'Well, maybe that's the way to do it.' "I think he liked the energy and speed of Motörhead, but he liked the epicness and the arrangements of Diamond Head. And the two crossed over into Metallica." Metallica later repaid Diamond Head's hospitality and influence by recording three of Diamond Head's songs for singles and EPs. "All of the major bands I was into at the time had their own identities," says Ulrich, who had been a ranked tennis junior back in Denmark but by 1981 had bagged his career at the nets to concentrate on drumming. "They weren't just copying everyone else and taking the easy way out."

Ulrich had one aborted jam session with Hetfield, who had responded to Ulrich's ad in a local paper, in the spring of '81. "He had just given up tennis to play drums," Hetfield says, "and he had one cymbal that kept falling over. We had to stop while he fixed it." When they tried again, after Ulrich's return from England, something clicked. They soon recorded their first original, a rocker à la Motörhead called "Hit the Lights." They persuaded Brian Slagel to put it on Metal Massacre, even though the sound was less than professional, they'd never played live and the band in fact had no other regular members. Hetfield's roommate, Ron McGovney, played bass, a black guitarist, Lloyd Grant, did the solos, and Hetfield sang in a weird aggro castrato, part Ozzy, part Queen.

Within a year, Metallica was the talk of the burgeoning metal underground, thanks in great part to a roaring 1982 demo tape, No Life 'til Leather, made by Hetfield and Ulrich with McGovney and lead guitarist Dave Mustaine (who is now in Megadeth). Ulrich, an avid tape trader, sent free copies to his top tape contacts, knowing that if they liked it, they would copy it and pass it on. "Getting it to the record companies, it was never that serious," he says. "All we wanted to do was send it out to the traders, get mentioned in some fanzines." They did better than that. After hearing No Life 'til Leather, Jon and Marsha Zazula, who ran a hip metal-oriented record store in New Jersey, offered the band a record deal. Kill 'Em All – originally titled 'Metal up Your Ass' and changed, under vigorous band protest – was recorded for the Zazulas' own Megaforce label in 1983, by which time Cliff Burton had added his monster bass technique to the mix and Kirk Hammett had replaced Dave Mustaine.

Thus began the grueling but steady rise of the members of Metallica from underdog sensations to overground stars, living on little money and a lot of Hamburger Helper while developing reputations for both their napalm sound and their spirited drinking (which led to the colorful nickname Alcoholica). They also worked hard perfecting their novel songwriting technique. To this day, four albums later, a Metallica song always starts with the Riff Tapes. Each member puts down a selection of guitar or bass riffs on cassette (Lars hums his to James, who records them on guitar). The best of the lot are compiled on a master Riff Tape, which becomes the prime source material for an entire album. It's a kind of musical Scrabble wherein the band experiments with different melodies, hooks and segues, putting letter blocks together to make a word. "We trade the tapes, listen to them and pick out the riffs we feel are good enough to build songs around," says Hammett. Ulrich says Metallica's songs have become longer and more intricate – "... And Justice for All" and "To Live Is to Die," on the latest LP, both clock in at just under ten minutes – because the more bits they add to a song, the more time it takes to get back to the main verse and chorus.

But the grumbling from some metal hard-liners that Metallica's music has grown artier – and softer – as the band's bank balance has gotten bigger is, as Hetfield bluntly puts it, "fucking stupid." "We're still hungry," says Hetfield. "Maybe in a different way, not playing 100 mph anymore. You can't do that all the time. A lot of people just want to hear aaaargh! all the time." That's certainly true of many new thrash-metal bands formed in the wake of Metallica and its chief contemporaries, Anthrax, Megadeth and Slayer. Too few understand the difference between mere speed and real style. "We deal with extremes," says Ulrich, "because we don't want to get stuck on a narrow track. It's not fun to be predictable." Besides, speed-metal bands are like gunfighters. "Yeah, like 'Hey, we're the fastest band in the world,"' Hetfield snorts. "No, you're not. There's always someone faster."

To enter the Europa hotel in Belfast, Northern Ireland, you must first go through a security checkpoint, passing a high, slatted reinforced fence that separates the main doorway from the street. The rest of the hotel is ringed by chain-link fencing topped with menacing curls of barbed wire. Up in the rooms, visitors find complimentary matchbooks emblazoned with the words 'We're back.' The Europa, it turns out, has the dubious distinction of being the most bombed hotel in Europe – it's been hit twenty-nine times, according to the BBC in Northern Ireland. There are no reported incidents of sectarian violence during Metallica's overnight tour stop here. Still, in a city scarred by interminable religious and political civil war, where a fully armed British-army soldier patrols the back-stage area of the Antrim Forum with a bomb-sniffing German shepherd, it is eerie to hear a sellout mob of metalheads chant, "Die! Die! Die!" in unison while Metallica rips into "Creeping Death."

In fact, the song is about the Egyptian plagues, and the album it comes from, Ride the Lightning, is a chilling song cycle about the horror and finality of death, from the last thoughts of a deam-row prisoner (the title track) to the troubled meditations of a young person contemplating suicide ("Fade to Black"). For all they care, the Antrim maniacs might as well be shouting, "Beer! Beer! Beer!" "I was thinking some similar thoughts during the pyro stuff before 'One,"' Lars Ulrich says a couple of days later. "I was sitting there behind the back line, all these 'bombs' exploding onstage, and there are almost 3000 Northern Irish maniacs out there cheering." James Hetfield, who leads the nightly "Die!" chant, wasn't so bugged. For one thing, he says with a laugh, "not all my lyrics have 'creeping death' in them." For another, he adds soberly, you can't have life without death. "I don't know if it's just another word to the kids or not," says Hetfield. "I just feel all that's just a part of life. That title on the new album, 'To Live Is to Die,' is pretty fucking cool. That's what it's about in a way. Energy, whether it's negative or positive, can be a good thing."

Cliff Burton wrote the lyrics to that particular song – "When a man lies he murders/Some part of the world/These are the pale deaths which/Men miscall their lives/All this I cannot bear/To witness any longer/Cannot the kingdom of salvation/Take me home." That he didn't live to see them recorded is an irony hardly lost on Hetfield or the other members. Writing songs about death is one thing, confronting the real thing quite another. Hetfield vividly remembers sitting in a Swedish hospital the night of September 27th, 1986, after the band's bus overturned, killing Burton instantly. "Lars busted his toe, the side of Kirk's face was all swollen up, I was in shock," he says. "I remember we were getting ready to leave, and our tour manager said, 'We're going to get a cab for the band.' And when he said 'the band,' it was like 'Oh, God, the band? We're not a band right now."' In truth, Metallica had no intentions of breaking up after Burton's death. "If we had hung it up," says Hammett, "Cliff would have been so pissed off." Rarely seen in anything but unfashionable denim flares, idolized in the metal community for his volcanic bass solos, Burton epitomized the up-yours spirit of the band.

Indeed, Jason Newsted wasn't allowed to step casually into such crucial shoes. "It was a test all the time – windups from everyone to see if I could cut it," he says of his inaugural tour, a late-1986 visit to Japan. "Everybody would go down to the bar to have sushi and sake for days and charge it to my room. We'd go to take pictures at the temples, and they'd all get in one taxi and make me ride by myself. This went on for a year. If I was going to buckle, they had to know. I took it, and that was that."

James Hetfield says Burton's death gave many of his lyrics a stinging immediacy he'd never counted on. "People probably think, 'Oh, they're not going to do the heavy lyrics now because of what happened,"' he says. "Man, those lyrics mean a lot more to me now." But any suggestion that Metallica songs inspire fans to acts of violence – or worse, suicide – makes his nostrils flare. For example, "Fade to Black" is about the despondency that can lead to suicide, not the act itself. The words were directly inspired by the band's own sorry state of affairs after its gear was stolen and it was left stranded and broke in New Jersey shortly before a trip to Europe to make Ride the Lightning. "Dyers Eve," the powerful climax to ... And Justice for All, is not about parental hatred ("Dear Mother/Dear Father/What is this hell you have put me through") but rather is drawn from Hetfield's experience as the son of Christian Scientists. "They'd sit around and tell stories about somebody who got healed without medicine," says Hetfield. 'I remember this one little girl, she broke her arm, and they were saying, 'She didn't need a cast, she didn't need anything.' And if you looked at her arm, it was all fucked up – she couldn't use it properly. "I couldn't believe it. If you're going to believe in God, don't you realize God gave you the brains to be able to fix something like that right? I could not get into that at all, and I think that messed me up early on."

Many fans have found solace in Metallica's songs, such as the young man who won a win-dinner-with-Metallica contest on the Monsters of Rock Tour with a poignant essay about how he'd decided not to kill himself because of "Fade to Black." Hetfield is pleased that the music matters to people, but he is reluctant to take too much credit. At the same time, he says he can't take any responsibility for the crowd's reading of the "Die, die, die" chorale. "I write the lyrics for us," he states firmly. "Don't take it literally. Actually, I don't care if you do or not. I'm not telling you what to do, and I don't like people telling me what to do. Take it in your own way, but don't fucking blame it on me. That's the lame way out."

Backstage in Belfast, shortly before show time, Lars Ulrich and one of the band's managers, Peter Mensch, sit down with a CD player and a copy of ... And Justice for All. They listen to the song "One" over and over again, analyzing the arrangement for potential edits. The idea is to get the seven-minute song down to a manageable length for AOR radio and possible release as a single. "They're like the Grateful Dead of heavy metal," Mensch had said of his charges the night before. "They can sell so much on their own, as they are. To take it further, it means edit a song for a single, do a video – all the usual stuff. And they realize that's the only way to expand the audience. It's not like the Sixties, when something really outside could make a mainstream impact."

Ulrich is extremely sensitive to the slightest implication that editing a single constitutes immediate sellout. He notes that the group released an edited version of "For Whom the Bell Tolls" back in 1984, "but no one cared, because then it was just little shitty Metallica. Now 900,000 more people have bought the records, and it's a big deal. "If you stay on top of what's going on and keep an open mind, you can make a lot of that shit work for you. If we take a minute and a half out of this track to expose another 300,000 kids to the other eight tracks on the album, is that a good way to do it?"

On last summer's Monsters of Rock Tour with Van Halen, Scorpions and Dokken, Metallica picked up a few clues about the wrong ways to do it. "Scorpions," says Kirk Hammett, "you can tell that they were playing the exact same show every time they played – exact same moves, choreography. There was no spontaneity in it. It was like a business for them." "I don't mean any disrespect to them at all," Jason Newsted says, "but they would always have their rock act on. They can't turn it off. You'd be having breakfast in the airport at a snack bar, they'd still be on the rock act. How can you live your life like that?" There is definitely a point, Ulrich says, beyond which Metallica will never go. "One thing you won't see this band do is go out on that one last tour, make that one last record for that extra $500,000 apiece," he says. "When the reasons of playing and having fun don't matter anymore, then we will have the sense to cut it off right there."

But what about the kids? The kids, as always, know better. "The kids," Newsted says, "are way smarter than people give 'em credit for. They can see right through you. If you don't mean it two or three albums down the line, they know it. And they'll say, 'Fuck off."' "Some friends of mine called me up," James Hetfield says, "and went, 'Hey, man, I hear you went platinum. Just quit and come home, give up and start a new thing. The new thing is to quit.' Can you imagine it?" He laughs. "METALLIC GOES PLATINUM AND QUITS." Then the next day's paper – METALLICA FANS ALL QUIT THEIR JOBS, SIT AT HOME, DRINK BEER, WATCH TV."